For example, elevated tumour tissue levels of uPA have prognostic impact in a variety of cancers such as breast, colon, oesophagus, ovary and stomach cancer, high antigen levels of uPAR are associated with poor prognosis in cancer of the breast and colon, and elevated levels of PAI-1 are correlated with shortened overall and/or disease-free survival in renal, ovarian and breast cancer (Duffy and Duggan, 2004; Clark et al, 2008). This evidence concerns the gene PLAU and breast cancer.